EXPERIMENTAL CORE SUMMARY More than 99% of known metabolites and chemicals cannot be identified in metabolomics studies because no reference materials or data exist for them. Therefore, a large number of metabolites remain unidentified, while a limited number of metabolites are identified repeatedly. The inclusion of many features that probe the molecular structure of metabolites, which can be consistently measured experimentally and accurately predicted computationally, is crucial for the success of any compound identification approach that transcends the paradigmatic-use of reference standards. We plan to utilize ion mobility-mass spectrometry (IM-MS), with tandem mass spectrometry (MS/MS), to provide quantitative measures of the shape and chemistry of molecules to characterize and identify molecules that otherwise are indistinguishable by current approaches. The Experimental Core will facilitate a transition past the need for reference standards by providing experimental validation of predicted molecular properties and computational models, experimental validation of a multi- property compound identification algorithm, and dissemination of data and SOPs for best utilization of experimental measurements and calculated molecular properties. This work is significant because it, in concert with a complementary Computational Core, supports the development of a new, paradigm-shifting metabolomics analytical methodology that greatly expands the number of biologically relevant compounds that can be quickly identified in metabolomics studies. This work is innovative because it implements accurate and reproducible measurement of multiple molecular properties, employs flexible measurement platforms and readily transferable protocols, and provides an next-generation IM-MS analysis platform.